The human voice is very flexible and we’ll look at the ways you can manipulate it. Remember though, that the voice uses muscle and you can strain it just as easily as an ankle. Pay attention and stop if anything hurts.

Your basic tools are Pitch, Placement, Pacing, Accent and Attitude.
Pitch is fairly self-explanatory. To check your range, hum from your highest to your lowest note. Of that, you probably mostly use the middle when speaking. While it can help color a character, it isn’t a good idea to rely on pitch alone to distinguish between characters, simply because you use more than one note while speaking.

Placement

There are several resonators which affect the tone of the voice. Put one hand on your chest and the other hand on your nose. Now hum through your range again. As you do, you’ll feel your chest vibrate at the low end and your nose vibrate in the upper middle. These are both resonators.

The facial mask has several other resonating cavities, which you mostly notice with a sinus infection. Ever wonder why you sound nasally with a cold?

You can move the voice from the front of the mouth to the back of the throat. Broadly speaking Russian tends to be at the back of the mouth while British English tends to be very forward.

I will now attempt to explain how to do this without being able to demonstrate. (Oy. Why did I think this was a good plan.) Okay, start with the nasal resonator, because it’s easiest to find.
-Hold your nose, say, “Nnnnnn” and try to get your nose to really buzz.
-Now remove your hand and try to talk, keeping your voice as nasally as possible. Use the phrase, “What did you say?” as your experimental phrase.
-Try adjusting the pitch while keeping the nasality.
A little bit of nasality can be used to make a “brighter” sound.

Next we’ll move to the back of the throat. Open your mouth in a yawn. Let your soft palate rise. Try to talk. Does it feel like your voice is at the back of your mouth? Again, play with pitch. Placing your voice at the back of your throat can make a “darker” sound.

Next, we’re going to move a series of consonants from the back of the mouth to the front. As you do this, pay attention to where your voice feels like it is during the “aaaah” portion of each consonant sequence. It will be subtle.
The series runs like this. Guh, guh, guh, guh, Gaaaah, Kuh, kuh, kuh, kuh, kaah, (I’m not going to write them all out, I’ll give you the consonants and you can figure out the pattern.) G, K, D, T, B, P.
Reverse it, moving from Puh to Guh.
Try saying our test phrase, “What did you say?” at each “location” in the mouth.

Roughly, and very loosely, that’s placement. I’ll talk about other aspects of placement when I discuss how to create specific types of voices like children and older people.

Moving on.

Pacing

This covers everything from how quickly a character speaks to the types of rhythms they use. Is their voice quick, but fluid or is it staccatto. Slow and halting, or does it drawl?

Note: Generally speaking, always speak slower than you think you should when reading.

Attitude

You can tell on the phone if someone is smiling, right? Technically, it’s a combination of the things we’ve already talked about, but fundamentally it’s about attitude. If you know your character, you’ll know how they speak.
Take the phrase, “What did you say?” Say it as if you are angry. Now, curious. Disbelieving? Great. Now say it like you’re a parent and a kid has just talked back to you. That is attitude. Attitude is your friend.

Accent

Chances are, this won’t be something you need to deal with. If you do have a character who has an accent for God’s sake, make sure you can do it convincingly. There’s nothing worse than hearing someone butcher an accent, it will destroy the credibility of your story faster than you can say “Run fer the hills.” There are a lot of tapes that deal with learning accents for actors. If you’re going to do it, do it right.

So, those are the basic tools. The nice thing about character voices is that you can be fairly subtle. Most of the time the Attitude and Pace will be enough. If you can affect Placement, that’s even better. What you are looking for is a voice that is distinct from the other voices and appropriate to the character. Of course, which of these tricks you use for each voice depends on the character for whom you are speaking.

Still, there are some basic types of voices, so I’ll talk about how to make a child’s voice as an example, and then later talk about aging voices and cross-gender voicing. A lot of this will be useful for other voice types.

The natural impulse for people is to shoot up into falsetto for kids’ voices. The trouble is that it alters the placement of your voice so much that it sounds ridiculous.

In singing one speaks of the Chest Voice, Middle Voice, Head Voice and Falsetto. Each of these resonates in a different place. Most people speak with their chest and middle voices–this includes children. So when you raise your voice too high to match a child’s pitch you move it into a different place.

The human voice uses a number of different muscles to generate sound. Generally speaking, the longer someone’s neck is the deeper their voice will be. So a child, with a short neck is also going to have a higher voice. In addition to the changes that happen at puberty, this has a huge impact on the pitch you hear.

That said, we respond tone as much as pitch. So to make a child’s voice, raise your pitch a little, but don’t try to do a literal match with kid.

The next thing is resonance. There are different resonating cavities that simply don’t develop until you’re an adult. To make a child’s voice you need to kill the resonance in your voice. Part of that happens by raising up to a head voice, which gets you away from your chest resonating cavity. Next, keep your soft palate down. And now try to make certain that you aren’t resonating in your nose, which you can do by pinching your nose. (Remember those exercises?)

You also need to add a tiny bit of aspiration. Aspiration is what happens when you allow more air to pass through your throat than is needed to produce sound. Remember the scene in My Fair Lady when Eliza is learning to pronounce her Hs? An H is an aspirated sound. People will also say something sounds “breathy” Think of Marilyn Monroe singing “Happy Birthday.” A little bit of aspiration helps make the voice sound less supported and younger.

Finally there’s the pronunciation. This is going to change depending on how young your child is, but in the under-10 camp things to listen for are more pronounced dipthongs and softer consonants.

Great, but what if there’s a piece with more than one kid? Remember Attitude and Pace. You can also still adjust placement by making one voice more or less nasal. Or having a voice that is breathier than the others. Again, with this or any character voice you don’t need to push far to make it distinctive.

With all voices, the main thing to focus on is telling the story, if a character voice prevents you from conveying emotion don’t use it.

One thing I’ve noticed with kids’ voices: you can often do a younger kid by speaking a little jerkily and/or overdeliberately. If you listen to children, you may find their sentence rhythms uneven, a little unnatural . . . or overly careful because they want to get it right. (That is, until they get to the speedy and slurry middle school/early high school years.)

I’m a little surprised by “always speak slower than you think you should when reading.” I’ve usually felt the opposite, partly because most people who have not practiced reading aloud a lot, don’t manage to read as quickly and smoothly as they speak. Ergo, other people are used to hearing you faster than you can read, assuming your articulation is reasonably sharp and clear.